An insurer of city's building settled with insured for loss resulting from collapse of portion of roof and then sued the architect and engineers charging that a latent defect had caused the collapse. The District Court, Laramie County, Alan B. Johnson, J., entered summary judgment for architect and engineers and insurer appealed. The Supreme Court, Rose, J., held that insurer acted as volunteer in settling, where its policy excluded loss caused by inherent or latent defect and the collapse was result of latent defect and insured could not recover on either theories of legal or investment subrogation.